Processor cards containing a data processing capability such as a microprocessor can be used as credit cards, debit cards, stored-value cards, membership cards, security access cards, identification cards and so on. Cards having a data processing capability are sometimes referred to as “smartcards”. Such cards are usually of a standardised size and shape, such as that prescribed in ISO 7810 for credit cards and debit cards etc., and tend to have information such as an indication of the card issuer, a card holder name, a card number and so on displayed in standard areas on the card surface on one side of the card. The opposing side of the card may comprise a magnetic or optical stripe and an area for the signature of a user of the processor card holder possibly contact details and other relevant party logos.
It is now possible to incorporate more and more functions within such cards. For example, it is now possible to incorporate dynamic displays in cards using, for example LCD or 8-segment displays; audio transmitters may also be incorporated using, for example, flat panel loudspeaker technology such as that produced by NXT™. However, incorporation of sophisticated functions, which may necessitate a user input interface, is inhibited by the limited available space on such cards due to the standardised size and the space taken up by information such as that described above.
Using processor cards to process transactions may involve entering the card into a reading terminal, which then reads information from the magnetic or optical strip and/or processor chip (via an array of contact pads on the front face of the card). The user inputs an identification code known only to the user such as a Personal Identification Number (PIN) into the terminal. The terminal and card interact to verify that the identification code matches a value stored in the card, in a known manner; the transaction only proceeds if there is a match, which prevents the card being used by third parties in the event that the card is lost or stolen.
However, there is a move to arrange processor cards for use in performing contactless transactions, in which the card communicates wirelessly with a terminal using, for example, inductive or capacitive activation and Radio Frequency Identification (RFID) technology; this may be implemented using, for example, EMV Contactless Communication Protocol Specification v.2.0. This allows transactions to be processed more quickly than methods involving entering an identification code, but gives rise to security issues; since the information on the card can be read wirelessly, it is possible that third parties could use portable terminals to read this information without the user's knowledge and subsequently make use of this information for nefarious purposes.
In some arrangements processor cards are used in conjunction with another device, such as a mobile telephone. A card may be inserted into the device, which then accesses data on the card and communicates wirelessly with a terminal using, for example, Near Field Communication (NFC) technology.